One important indicator of a microprocessor's performance is the speed with which the microprocessor can access data stored in memory. Multi-level cache systems are often employed to increase the speed of data access by storing data from frequently accessed memory locations in one or more caches. The microprocessor can access the data in the caches much faster than it can access data from main memory. The amount of time, or number of clock cycles, that elapses between when a location in cache is selected for reading or writing and when the data is available at the cache's output for access by the microprocessor is called the “latency” of the cache. Typically, the read latency of a cache is greater than the write latency because of the time it takes to place data values at the output of the cache (as opposed to simply inputting new values for writing). Thus, in general, caches having a low read latency can significantly increase the performance of the microprocessor.